A method for determining the crucible position during welding

Abstract

The present invention provides a method for determining the crucible position during welding, the steps of which include: performing reflection imaging of the lower edge of the guide tube in the main chamber and the liquid surface in the quartz crucible to obtain that the lower edge of the guide tube and the liquid surface of the quartz crucible are in the same graphic interface; performing the center of the arc surface 1 formed by the projection of the lower edge of the guide tube and the center of the arc surface 2 formed by the projection of the liquid surface of the quartz crucible are located on the same longitudinal line in the graphic interface; and then measuring the distance from the lower edge of the guide tube to the liquid surface in the quartz crucible. The present invention can quickly determine the position of the quartz crucible during welding, and accurately calculate the size of the crucible position. At the same time, it can also accurately determine the coaxial position of the guide tube and the quartz crucible, and can quickly adjust the guide tube to meet the welding needs and prepare for subsequent crystal pulling.

Description

Technical Field

[0001] The invention belongs to the technical field of Czochralski single crystal, and in particular relates to a method for determining a crucible position during welding. Background Art

[0002] In the process of CZ single crystal growth, the crucible position is determined by the interface auxiliary tool coordinate grid in the welding process. Affected by factors such as the installation position of the guide tube, the adjustment standard of the CCD field of view frame, the clarity of the centralized control interface field of view, and the judgment ability of personnel, the crucible position consistency is poor, which affects the temperature consistency of the crystallization area and the crystallization process, thereby affecting the crystallization rate and production efficiency. At the same time, at this stage, personnel manually adjust the crucible lift through the system prompt to determine the crucible position node for welding, which takes up a lot of work energy of the centralized control personnel to operate. Summary of the invention

[0003] The invention provides a method for determining the crucible position during welding, in particular for determining the crucible position of a quartz crucible during welding, which solves the technical problems in the prior art of poor crystallization rate and low working efficiency caused by adjusting the crucible position through manual prompting.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A method for determining a crucible position during welding, comprising the steps of:

[0006] Performing reflection imaging of the lower edge of the guide tube in the main chamber and the liquid surface in the quartz crucible to obtain the lower edge of the guide tube and the liquid surface of the quartz crucible in the same graphical interface;

[0007] The center of the first arc surface formed by the projection of the lower edge surface of the guide tube and the center of the second arc surface formed by the projection of the liquid surface of the quartz crucible are located on the same longitudinal line in the graphic interface;

[0008] Then, the distance from the lower edge of the guide tube to the liquid surface in the quartz crucible is measured.

[0009] Furthermore, the centers of the arc surface 1 and the arc surface 2 are both placed on the longitudinal line where the intersection of the diagonals of the graphic interface is located.

[0010] Furthermore, the center of the arc surface 1 overlaps with the intersection of the diagonal lines of the graphic interface.

[0011] Furthermore, the first arc surface and the second arc surface are located on the same side of the position of the seed crystal in the graphic interface.

[0012] Furthermore, the position of the seed crystal in the graphic interface is the position of the intersection of the diagonals of the graphic interface.

[0013] Furthermore, the two endpoints of the arc surface one and the two endpoints of the arc surface two are both located on the edge of the projected circle in the graphic interface; and the arc surface one is located on the edge of the projected circle in the graphic interface.

[0014] Furthermore, the second arc surface is placed inside the first arc surface; the second arc surface and the first arc surface are both symmetrically arranged relative to a longitudinal center line perpendicular to the intersection of the diagonals of the graphic interface.

[0015] Furthermore, the step of measuring the distance from the lower edge of the guide tube to the liquid surface in the quartz crucible includes:

[0016] Based on the lens illumination angle of the CCD camera placed outside the main chamber and the camera pixels;

[0017] The distance from the lower edge of the guide tube to the lowest point of the liquid surface in the quartz crucible is obtained, which is the crucible level value of the quartz crucible.

[0018] Furthermore, it also includes: obtaining the absolute value of the maximum height and the minimum height difference between the lower edge of the guide tube and the liquid surface in the quartz crucible;

[0019] When the absolute value of the difference between the maximum height and the minimum height from the lower edge of the guide tube to the liquid surface in the quartz crucible is within the range of 0-1.2 mm, the position of the guide tube is correctly set;

[0020] When the absolute value of the difference between the maximum height and the minimum height from the lower edge of the guide tube to the liquid surface in the quartz crucible is greater than 1.2 mm, it means that the guide tube position is tilted; then adjust the guide tube position.

[0021] Furthermore, the camera projection angle is 75° relative to the liquid surface of the quartz crucible.

[0022] By adopting the method designed in the present invention, the position of the quartz crucible during welding can be quickly determined, and the crucible size can be accurately calculated. At the same time, the coaxial position of the guide tube and the quartz crucible can be accurately determined, and the guide tube can be quickly adjusted to meet the welding needs and prepare for subsequent crystal pulling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of a projection graphic interface according to an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure in the main chamber during welding according to an embodiment of the present invention.

[0025] In the figure:

[0026] 10. Graphical interface 20. Arc surface 1 30. Arc surface 2

[0027] 40, seed crystal projection 50, projection circle 60, main chamber

[0028] 70, camera 80, guide tube 90, quartz crucible

[0029] 100. Seed Crystal DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] This embodiment provides a method for determining the crucible position during welding, such as Figure 1-2 As shown, the steps include:

[0032] S1. Perform reflection imaging of the lower edge of the guide tube 80 in the main chamber 60 and the liquid surface in the quartz crucible 90 to obtain that the lower edge of the guide tube 80 and the liquid surface of the quartz crucible 90 are in the same graphic interface 10.

[0033] Specifically, in the main chamber 60, a weight with a seed crystal 100 is suspended upside down by a steel rope, and then penetrates the guide tube 80 and immerses in the liquid surface of the quartz crucible 90. A CCD camera 70 placed on the outer wall of the main chamber 60 projects into the main chamber 60 to observe the melting of the liquid surface in the quartz crucible 90.

[0034] The camera 70 is tilted at an angle of 75° relative to the liquid surface of the quartz crucible 90. The shooting angle can completely project the lower edge of the guide tube 80 onto the screen of the external terminal device electrically connected thereto to form a screen as shown in FIG. Figure 1 and the camera 70 can also completely capture the image of the seed crystal 100 being fused, and the liquid level in the quartz crucible 90 can be observed, and the seed crystal 100 will not be affected.

[0035] After the camera 70 projects, a projection circle 50 is displayed on the graphic interface 10, wherein the projection of the lower edge of the guide tube 80 and the projection of the liquid surface in the quartz crucible 90 are both displayed on and inside the projection circle 50. The outer frame of the graphic interface 10 is a regular polygon structure, and the intersection of its diagonals overlaps with the center O of the projection circle 50.

[0036] S2. The center O of the arc surface 1 20 formed by the projection of the lower surface of the guide tube 80 and the center o of the arc surface 2 30 formed by the projection of the liquid surface of the quartz crucible 90 are located on the same longitudinal line in the graphic interface 10.

[0037] Specifically, the projection of the lower edge surface of the guide tube 80 is adjusted first to form an arc surface 20 .

[0038] Adjust the focal length of the camera 70 to obtain the projection of the lower edge of the guide tube 80, whose position on the graphical interface 10 is the arc surface 1 20. It is located on the edge of the projection circle 50, and the center O of the arc surface 1 20 and the center o of the projection circle 50 are on the same longitudinal axis.

[0039] The projection of the liquid surface in the quartz crucible 90 is then adjusted to form an arc surface 30 .

[0040] The focal length of the camera 70 is adjusted to obtain the projection of the liquid surface of the quartz crucible 90 , whose position on the graphic interface 10 is the arc surface 2 30 , which is located inside the projection circle 50 and inside the projection arc surface 1 20 of the lower edge surface of the guide tube 80 in the graphic interface 10 .

[0041] Of course, the order of adjusting the projection of the lower edge surface of the guide tube 80 and adjusting the projection of the liquid surface in the quartz crucible 90 can be interchanged.

[0042] Finally, the center O of the first arc surface 20 and the center o of the second arc surface 30 are adjusted to be located on the same longitudinal line.

[0043] The center O of the arc surface 1 20 and the center o of the arc surface 2 30 are both located on the longitudinal line where the diagonal intersection of the graphic interface 10 is located, that is, located on the central longitudinal axis of the graphic interface.

[0044] Preferably, the center O of the first arc surface 20 overlaps with the intersection of the diagonal lines of the graphical interface 10 ; and the center o of the second arc surface 30 is located below O of the center of the first arc surface 20 .

[0045] The arc surface 1 20 and the arc surface 2 30 are both located on the same side of the seed crystal 100 in the graphical interface 10, that is, from Figure 1 As can be seen, they are all located at the upper part of the graphical interface 10. The position of the seed crystal 100 in the graphical interface 10 is the position where the diagonal lines of the graphical interface 10 intersect, that is, the projection point of the seed crystal 100 is located at the center point of the graphical interface 10.

[0046] Furthermore, both end points of the arc surface 1 20 and both end points of the arc surface 2 30 are located on the edge of the projected circle in the graphic interface 10 ; and the arc surface 1 20 is located on the edge of the projected circle in the graphic interface 10 .

[0047] Preferably, the second arc surface 30 is disposed inside the first arc surface 20 ; the second arc surface 30 and the first arc surface 20 are both symmetrically arranged relative to the longitudinal center line perpendicular to the intersection of the diagonals of the graphical interface 10 .

[0048] S3. Calculate the distance H between the lower edge of the guide tube 80 and the liquid surface in the quartz crucible 90.

[0049] Based on the lens illumination angle of the CCD camera 70 placed outside the main chamber 60 and the pixels of the camera 70, the system can automatically capture the position of the lowest point and the highest point in the liquid surface of the quartz crucible 90. According to the relationship between the pixels of the camera 70 and the diameter photographed by the camera 70, a coefficient can be obtained, and then according to the coefficient and the pixel values ​​corresponding to the positions of the lowest point and the highest point in the liquid surface of the quartz crucible 90, the distance from the lower edge of the guide tube 80 to the lowest point and the highest point in the liquid surface of the quartz crucible 90 can be calculated. This calculation method is obtained by the system itself and will not be described in detail.

[0050] The distance from the lower edge of the guide tube 80 to the lowest point of the liquid surface in the quartz crucible 90 is obtained as the crucible position value H of the quartz crucible 90 .

[0051] Furthermore, in order to determine the accuracy of the position setting of the guide tube 80 , the absolute values ​​of the maximum and minimum height differences between the lower edge of the guide tube 80 and the liquid surface in the quartz crucible 90 may be obtained.

[0052] When the absolute value of the difference between the maximum height and the minimum height between the lower edge of the guide tube 80 and the liquid surface in the quartz crucible 90 is within the range of 0-1.2 mm, it indicates that the position of the guide tube 80 is correctly set.

[0053] When the absolute value of the difference between the maximum height and the minimum height between the lower edge of the guide tube 80 and the liquid surface in the quartz crucible 90 is greater than 1.2 mm, it means that the position of the guide tube 80 is tilted. If the position of the guide tube 80 is tilted, it is necessary to stop the furnace, adjust the axial position of the guide tube 80, and then restart the welding to confirm the crucible position value of the quartz crucible 90.

[0054] By adopting the method designed in the present invention, the position of the quartz crucible during welding can be quickly determined, and the crucible size can be accurately calculated. At the same time, the coaxial position of the guide tube and the quartz crucible can be accurately determined, and the guide tube can be quickly adjusted to meet the welding needs and prepare for subsequent crystal pulling.

[0055] The above embodiments of the present invention are described in detail, and the contents are only preferred embodiments of the present invention, and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for determining the crucible position during welding, characterized in that the steps include: Performing reflection imaging of the lower edge of the guide tube in the main chamber and the liquid surface in the quartz crucible to obtain the lower edge of the guide tube and the liquid surface of the quartz crucible in the same graphical interface; The center of the first arc surface formed by the projection of the lower edge surface of the guide tube and the center of the second arc surface formed by the projection of the liquid surface of the quartz crucible are located on the same longitudinal line in the graphic interface; Then, the distance from the lower edge of the guide tube to the liquid surface in the quartz crucible is measured; The centers of the arc surface 1 and the arc surface 2 are both placed on the longitudinal line where the intersection of the diagonals of the graphic interface is located; The center of the arc surface 1 overlaps with the intersection of the diagonal lines of the graphic interface; The center of the arc surface 2 is located below the center of the arc surface 1; The two endpoints of the arc surface 1 and the two endpoints of the arc surface 2 are both located on the edge of the projected circle in the graphic interface; and the arc surface 1 is located on the edge of the projected circle in the graphic interface.

2. A method for determining a crucible position during welding according to claim 1, characterized in that: The first arc surface and the second arc surface are located at the same side of the position of the seed crystal in the graphic interface.

3. A method for determining the crucible position during welding according to claim 2, characterized in that: The position of the seed crystal in the graphic interface is the position of the intersection of the diagonals of the graphic interface.

4. A method for determining a crucible position during welding according to claim 1, characterized in that: The second arc surface is placed inside the first arc surface; the second arc surface and the first arc surface are both symmetrically arranged relative to a longitudinal center line perpendicular to the intersection of the diagonal lines of the graphic interface.

5. A method for determining the crucible position during welding according to any one of claims 1 to 4, characterized in that: The step of measuring the distance from the lower edge of the guide tube to the liquid surface in the quartz crucible includes: based on the lens illumination angle of the CCD camera placed outside the main chamber and the camera pixels; obtaining the distance from the lower edge of the guide tube to the lowest point in the liquid surface in the quartz crucible, which is the crucible position value of the quartz crucible.

6. A method for determining the crucible position during welding according to claim 5, characterized in that: Also includes: Obtaining the absolute value of the maximum height and the minimum height difference between the lower edge of the guide tube and the liquid surface in the quartz crucible; When the absolute value of the difference between the maximum height and the minimum height from the lower edge of the guide tube to the liquid surface in the quartz crucible is within the range of 0-1.2 mm, the position of the guide tube is correctly set; When the absolute value of the difference between the maximum height and the minimum height from the lower edge of the guide tube to the liquid surface in the quartz crucible is greater than 1.2 mm, it means that the guide tube position is tilted; then adjust the guide tube position.

7. A method for determining the crucible position during welding according to claim 6, characterized in that: The camera projection angle is 75° relative to the liquid surface of the quartz crucible.

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